The invention relates to a folding top for vehicles of the type having a main bow which is pivotable about a vehicle transverse axis between top closed and open positions. Control arms are interconnected with respective lateral struts of the main bow. A pair of roof skin retaining rails are arranged laterally outside the respective lateral struts of the main bow and are movable between a top closed position where they hold the roof skin taut in position with their lower ends supported at vehicle side-boards and a top open position with the lower ends removed from the side-boards and inwardly of the struts to accommodate stowage.
Reference is made also to related, commonly assigned U.S. patent application Ser. No. 07/223,368, filed on even date herewith, and based on German Patent Application No. P 37 24 532.5, filed July 24, 1987 in Germany. This related application discloses other aspects of referenced embodiments of a convertible folding top.
Such a folding top is described in German Patent Specification No. 3,523,433. The width of entry of such a folding top during lowering into an assigned stowage compartment for the top is in this case clearly smaller than its maximum width when the top is closed, so that it can be accommodated without any problems in compartments for tops of motor cars having a tapered rear end, which are becoming increasingly widespread for aerodynamic reasons. At the same time, operating convenience is not impaired since the reduction in width during swinging back of the main bow takes place automatically. To control the roof skin retaining rails dependently on the swing-back angle of the main bow, a toggle lever is articulated between these rails and the assigned struts of the top on both sides in the proximity of the side-board upper edges, the toggle joint of which lever is supported on a compartment strut cover plate, arranged underneath the roof skin retaining rails, when the roof skin retaining bows are spread. This support absorbs the pretensioning forces of a return spring, which tends to pull the roof skin retaining rail into the swung-in folding position. Due to this toggle lever arrangement, during the shifting of the main bow from its upright position, a sliding process of the toggle joint or of the setting screw on the compartment strut cover plate on the toggle joint side inevitably occurs. This sliding process is accompanied by undesirable grinding noises, since it is necessary to refrain from lubricating the sliding surface for reasons of the risk that passengers in the vehicle may be soiled. Since, in addition, the head of the setting screw only rests at a point on the compartment strut cover plate during the sliding process, a relatively high contact pressure is produced. which may result in surface damage to the compartment strut cover plate.
A object of the invention is to further develop a folding top of the above-noted type in such a way that any occurrence of disturbing grinding noises during the course of the swinging in or out of the roof skin retaining rails and any occurrence of surface damage to visible side-board surfaces are reliably avoided.
This object is achieved according to the invention in that adjustment mechanisms for controlling movement of the roof skin retaining rails are arranged independently of the side-boards and are forcibly controlled by utilizing the relative movement between the lateral struts of the top main bow and the control arms taking place during the shifting of the main bow. This type of a mechanical forced control of the roof skin retaining rails is completely isolated physically and functionally from the vehicle side board edge structure.
According to certain preferred embodiments of the invention, it is provided that the adjustment mechanisms are actuated independently of the side-boards and that the lower ends of the roof skin retaining rails can move, in a first phase of the swing-back movement of the main bow, automatically into a position laterally and vertically spaced from the side-boards. In this embodiment, the adjustment mechanisms can be arranged directly at or over the board edges of the vehicle if they can be moved upwards away from the side-board edges together with the ends of the roof skin retaining rails. Otherwise, a sufficient vertical distance from the board edges must be maintained in this arrangement.
An important advantage of this alternative solution is, however, to be seen in that, beyond achieving the object of the invention, it is possible to use roof skin retaining rails on the folding top which overlap somewhat the outer contour of the side-boards near the board edges when the top is closed. With such a roof tile-like overlap, in which the roof skin fastened to the roof skin retaining rail around its lower end region is also involved, a reliable sealing of the connecting joint of the folding top to the structure is ensured more easily.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.